asp.net ¿Í»§¶Ë»º´æ(ClientCaching)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
StartClientCaching();
}
private void StartClientCaching()
{
//Ö¸¶¨»º´æʱ¼ä
int secondsTime = 30;

string headers = Request.Headers["If-Modified-Since"];
long nowTicks=DateTime.Now.Ticks;
long modifiedTick = DateTime.Parse(Request.Headers["If-Modified-Since"]).Ticks;
long ticks = nowTicks - modifiedTick;
if (headers != null && TimeSpan.fromTicks(ticks).Seconds < secondsTime)
{
Response.Write(DateTime.Now);
Response.StatusCode = 304;
// ÕâÖÖ·½Ê½»á²úÉú“´Ë²Ù×÷ÒªÇóʹÓà IIS ¼¯³É¹ÜÏßģʽ¡£ ”µÄÒì³£
//Response.Headers.Add("Content-Encoding", "gzip");
// Response.Headers.Add ºÍ Response.AddHeader µ«ÊÇÔÚMSDNÖÐÃ÷ȷд³ö£¬ÕâЩ¶¼ÊÇΪÁ˼æÈÝASP£¬ÔÚ.NET 3.5ÒªÇóʹÓÃÏÂÃæÕâÖÖ·½Ê½¡£
//ÕâÖÖ·½Ê½²»»á³öÏÖÒì³£
Response.AppendHeader("Content-Encoding", "gzip");
Response.StatusDescription = "Not Madified";
}
else
{
Response.Write(DateTime.Now);
SetClientCaching(Response, DateTime.Now);
}
}
private void SetClientCaching(HttpResponse response, DateTime lastModified)
{
//½«ETag Http±êÍ·ÉèÖÃΪÖƶ¨×Ö·û´®
response.Cache.SetETag(lastModified.Ticks.ToString());
//½«Last_Modified Http±êÍ·ÉèÖÃΪÌṩµÄSystem.DateTimeÖµ
response.Cache.SetLastModified(lastModified);
//½«Cache-Control ±êÍ·ÉèÖÃΪSystem.Web.HttpCacheabilityÖµÖ®Ò»
response.Cache.SetCacheability(System